hopefully fix muxado panics
hopefully fix muxado panics

I think passing a nil net.Conn was the culprit. It was deceptive
because the test wasn't always failing during the test containing
the nil. I suspect muxado was cleaning up the connection after the
test had already returned, so the panic was triggered in the middle
of the next test.

ChrisSchinnerl/Sia,rivine/rivine,mnsl/Sia,NebulousLabs/Sia,johnathanhowell/Sia,mtlynch/Sia,mnsl/Sia,NebulousLabs/Sia,ChrisSchinnerl/Sia,rivine/rivine,Mingling94/Sia,mtlynch/Sia,mharkus/Sia,MrStrong/Sia,mharkus/Sia,MrStrong/Sia,ericflo/Sia,ericflo/Sia